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Old Oct 06, 2012, 01:11 PM
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United States, NE, Hebron
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would a larger wing root be more advantages?

first this is just something i am wondering. i understand that typical sailplanes see advantages to high aspect ratios for speed and flight.

but what a typical DS ship sees is different than most others in that a
DS sailplanes sees way more stupid amounts of lift then any other sailplane. i am talking the horizontal lift or wind we use over the top of the ridge. the wind is not lift as we usually interpret it but our planes see it as such in a DS circuit hence the gain in speeds. with a 40mph wind the whole air mass is lift at 40mph and even higher at the concentrated lip. i see DS builders taking advantage of this by making the planes larger giving more area of lift to there plane. i think that they are finding a limit to the size or amount of drag that overcomes the lift factor on the record setting hills or they are just to big to keep in the sweet spot.



so my question and yes i under stand that a longer cord sees more drag but Would it not be more advantages to build a traditional DS ship with a larger wing root to take advantage of the lift but still keeping wing tips smaller and airfoils sleek. a wing in proportions with a JW but on a traditional plane with tail feathers.

i am just wondering if this has been looked at in a non traditional since. with the longer wing root you would have more lift area without increasing frontal area but yes increase drag.

just thinking and i am probably way off track but unsure so i ask the questions.

later Andrew K
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Last edited by 57sailplane; Oct 06, 2012 at 01:57 PM.
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Old Oct 07, 2012, 12:22 AM
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I am not sure if you are thinking of building something, but if you are I say build what you think will work and test it out. There are a few low aspect planes out there and there have been a few with a lot of taper ratio, but ultimately we have to face the reality that fastest planes have high aspect and relatively benign taper.
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Old Oct 07, 2012, 01:28 AM
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The speed multiplier a DS plane achieves over the wind speed is
directly proportional to its L/D. Lower aspect wings have a lower L/D thus will
go slower in the same wind than a higher aspect, higher L/D wing.

ian
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Old Oct 07, 2012, 10:03 AM
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so a plank style ship that has the larger wing root is using it as merly stability and strength and giving up some L/D? and thus speed?
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Old Oct 07, 2012, 11:20 AM
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Pretty much, yes. Same plank would be faster with higher aspect ratio, given same wing area.
But keep in mind a smaller root chord also means thinner airfoil, thus harder to make it stiff enough
to prevent flutter and so forth. High aspect ratio planks are also tend to be hard
to slow down to land and really hard to CG. Until recently most planks were foamies so build rigidity
was a big issue, but that's changing so we're seeing some thinner higher aspect
ratio molded examples.

ian
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Old Oct 07, 2012, 02:32 PM
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